I. Field of the Invention
This invention relates generally to communication systems. More specifically, the invention relates to a communication system having multiple processors to process data.
II. Description of the Related Art
The use of wireless communication systems for the transmission of digital data is becoming more and more pervasive. In a typical wireless system, a digital data network is connected to a plurality or remote units via a hub station and satellite. The satellite receives signals from the remote units and forwards them to the hub station. The hub station then transmits the signals to the digital data network. The path from the remote units to the digital network is referred to as a reverse link.
According to the prior art, each processor in the hub station is assigned to service a fixed group of channel buffers. In order to prevent overflow of the channel buffers, the processing resources of the processor assigned to a group of channel buffers must exceed the worst case expected processing demands of the group of channel buffers. However, by providing a processor which has more processing resources than the worst case processing demand of the group of channel buffers to which it is assigned, some of the processor""s resources will remain unutilized at all times. When as the number of groups of channels increases, the unutilized processor resources increases proportionately. In some cases, the cumulative unutilized processing resources in a system can exceed the processing resources provided by multiple processors.
For example, in a system in which the worst case processing demands of a group of 3 channel buffers is 2.1 Mega-instructions per second and the processor assigned to service the group of channel buffers is 2.5 Mega-instructions per second, 400 kila-instuctions per second of the processor""s resources remain unutilized at all times. If the same system has 300 channel buffers, 100 processors are used to service 100 groups of channels. In such a case, the cumulative unutilized processing resource is 40 Mega-instructions per second or the equivalent processing power of about 16 processors. Such extravagant under-utilization of processing resources increases the cost, power consumption, size and heat dissipation requirements of the system.
Therefore, there is a need for a system and method of reducing the amount of un-utilized processing power that are present in the hub station, yet ensuring that data communications being routed through the hub station are handled in a timely manner.
One embodiment of the invention includes a system comprising a communication system, comprising at least one remote unit, a satellite in operable communication with the at least one remote unit, a hub station in operable communication with the satellite, the hub station comprising a plurality of channel buffers for storing databits received from the satellite at the hub station, each of the channel buffers having an associated last-processed time, and a plurality of processors, wherein each of the processors respectively analyzes each of the plurality of channel buffers, and wherein each of the plurality of processors determines with respect to a currently selected channel buffer whether the currently selected channel buffer has sufficient amount of databits to process, the determining comprising determining a current time, and determining whether the difference in time between the current time and the last-processed time associated with the currently selected channel buffer is greater than a threshold, and wherein each of the processors processes the databits upon the determination that the currently selected channel buffer for the processor has a sufficient amount of databits to process, and wherein the each of the processors determines whether the databits have been processed by another one of the processors by performing a compare/exchange command with respect to the last-processed time that is associated with the selected channel buffer.
Another embodiment of the invention includes a method of identifying one or more databits for processing in a communication system, the method comprising successively storing one or more databits in a channel buffer, wherein the databits collectively comprise a data stream, determining a data rate for the data stream, determining a start location in the channel buffer, the art of determining based at least in part upon the data rate, a last-processed time that is associated with the channel buffer, and the size of the channel buffer, and determining an end location in the channel buffer.
Yet another embodiment of the invention includes a system for identifying one or more databits for processing in a communication system, the system comprising means for successively storing one or more databits in a channel buffer, wherein the databits collectively comprise a data stream, means for determining a data rate for the data stream, means for determining a start location in the channel buffer, the determining means acting based at least in part upon the data rate, a last-processed time that is associated with the channel buffer, and the size of the channel buffer, and means for determining an end location in the channel buffer.